Research and Design of Automatic Test System for Ventilator Performance / 中国医疗器械杂志

Ventilator is an important medical instrument which can replace the function of autonomous ventilation artificially. Its safety and reliability are related to the health and even life safety of patients. With the publishing of the new national standard and international standard for ventilators, higher requirements are put forward for the detection and evaluation. This study mainly introduces an automatic test system for ventilator performance. The test system is based on PF-300 air-flow analyzer of Imtmedical and standard simulation lung. The automatic switch module of simulation lung is developed, and the automatic test system of ventilator is designed using the software development platform based on Python. It can not only automatically test all ventilation control parameters and monitoring parameters of the ventilator, but also realize automatic data recording, form reports and data analysis, and improve the efficiency and quality of inspection, detection and quality control.

¿Cuál es la efectividad de los filtros de aire HEPA/MERV para disminuir la transmisión de SARS-CoV-2 en espacios cerrados en comparación con condiciones habituales sin filtro?: síntesis rápida de evidencia / How effective are HEPA/MERV air filters in reducing SARS-CoV-2 transmission in enclosed spaces compared to typical unfiltered conditions?: Rapid evidence synthesis

ANTECEDENTES Y OBJETIVO La actual pandemia de COVID-19 ha traído desafíos en las formas de prevención, como la ventilación de espacios cerrados. Mantener espacios ventilados, ha sido recomendado para disminuir la transmisibilidad de COVID-19. Ante este escenario, el uso de filtros de aire, tipo HEPA (High Efficiency Particulate Air) o MERV (Minimum Efficiency Reporting Value) ha tomado relevancia para mantener una carga viral baja en espacios cerrados. En este contexto la Secretaría Técnica Ejecutiva de la Comisión Nacional de Respuesta Pándemica solicita este resumen con el objetivo de determinar la efectividad del uso de los filtros tipo HEPA o MERV frente a condiciones de ventilación habitual en espacios cerrados no hospitalarios. METODOLOGÍA Se buscaron revisiones sistemáticas que respondieron la pregunta en las bases de datos MEDLINE y EMBASE a través de OVID y en Epistemonikos, con fecha 03 de junio de 2022. Además, se construyó una matriz de evidencia con el objetivo de encontrar literatura adicional y se realizó citación cruzada a través Google Scholar. Se utiliza la metodología de la certeza de evidencia GRADE. Los criterios de inclusión son: efectividad filtros HEPA o MERV, virus SARS-CoV-2, y Espacios cerrados Los criterios de exclusión son: ambientes hospitalarios, y los Patógenos no SARS-CoV-2. RESULTADOS Se utilizó una revisión sistemática, de la cual se obtuvieron los siguientes resultados: -No se encontró evidencia de efectividad de filtros MERV en el contexto de prevención de SARS-CoV-2. -No se encontró evidencia sobre efectividad de filtros HEPA en contexto escolar. -Se encontraron 2 estudios de modelamiento que evalúan la probabilidad de contagio por SARS-CoV-2 en espacios cerrados con filtro HEPA. -Con baja certeza en evidencia se observa que el uso de filtros HEPA junto a mascarillas N95 en espacios cerrados tiene un efecto imperceptible sobre la probabilidad de contagio por SARS-CoV-2 en comparación al no uso. -Con moderada certeza en la evidencia se observa que el uso de filtros HEPA cuando no se está en uso de mascarilla en espacios cerrados similares a oficinas disminuye la probabilidad de contagio por SARS-CoV-2 en comparación a no usarlos.

Circuit Designed for Driving Blower in Non-invasive Positive Airway Pressure Respirator / 中国医疗器械杂志

One of critical technologies in a non-invasive positive airway pressure respirator is to output the airflow for meeting the requirement of respiratory patient in breath. In order to develop a safe and reliable blower driving system, a circuit based on the special chips MC33035 and MC33039 was designed. The linear relationship between the input control voltage and the output air flow was achieved. This designed circuit will be embedded in the non-invasive ventilator system as a module. And based on this circuit, the secure and controllable ventilation flow can be performed.

Nova análise das vias aéreas superiores através de radiografias Panorâmicas: correlacionando seus locais de estreitamento, fluxo respiratório e de dor Orofacial / New analysis of upper airways using Panoramic radiographies, correlating narrowing sites, respiratory airflow and orofacial pain

A pesquisa teve como objetivo avaliar se radiografias panorâmicas de boca fechada podem ser usadas para observação dos tecidos moles e resistência do fluxo aéreo nas vias aéreas (VA), principalmente da faringe (naso, velo, oro e hipofaringe). Para averiguação do potencial obstrutivo das vias aéreas foram estudados 65 indivíduos adultos (54 do gênero feminino e 11 do gênero masculino), 45 com dores orofaciais e 20 assintomáticos. Estabeleceram-se parâmetros através de uma nova análise radiográfica para avaliação da presença de estruturas de tecido mole potencialmente obstrutoras do fluxo respiratório. Investigou-se a influência que a dor orofacial poderia exercer no fluxo aéreo destas vias respiratórias da cavidade nasal até a entrada dos pulmões. Estes parâmetros foram correlacionados à presença e localização de obstruções de vias aéreas (VA), através da técnica de oscilometria, mensurando diferenças do fluxo aéreo durante o repouso por via nasal e bucal. Secundariamente averiguou-se a possibilidade do uso das radiografias panorâmicas para a determinação da classificação de Angle dos pacientes determinada clinicamente. A classe molar de Angle foi confirmada com facilidade através das radiografias panorâmicas de boca fechada, acrescida da vantagem de visualização bilateral da mandíbula, ao invés da superposição dos lados direito e esquerdo como ocorre nas radiografias cefalométricas, comumente utilizadas para este fim. Concluiu-se que as radiografias panorâmicas de boca fechada são úteis para visualização e investigação preliminar de tecidos moles e do fluxo das vias aéreas superiores, principalmente da nasofaringe, velo e orofaringe, e a cavidade nasal, permitindo a detecção de locais com estreitamento potencialmente obstrutivos ao fluxo aéreo. A análise panorâmica facilitou a avaliação da simetria entre os lados direito e esquerdo das estruturas supracitadas. A presença de dor orofacial não influenciou o fluxo aéreo das VAS(AU)

The objective of this study was to evaluate the use of closed-mouth panoramic radiographs for visualization of soft tissues and airflow resistance of upper airways, especially the pharynx (naso, velo, oro, and hipopharynx regions). This study analyzed 65 adult individuals (54 of the feminine gender and 11 of the masculine gender), 45 with orofacial pain and 20 with no symptoms. Parameters were stablished using a new radiographic analysis for evaluation of the potentially obstructive soft tissues in the airways from the nasal cavity to the lungs. The influence of orofacial pain on the respiratory airflow was investigated. These parameters were correlated to the presence and level of the airway obstruction (VA), using forced oscillation technique or oscillometry were measured by the nose and mouth. The Angle's classes previously determined on the clinical way were verified. The results demonstrated that the closed-mouth panoramic radiographs can be used to soft tissues visualization and initial investigation of airways, mostly at nasopharynx and oropharynx, their potentially obstructive sites, nasal cavity, symmetry between right and left sides of these structures. The analysis of the results also demonstrated, as a specific objective, that the closed-mouth panoramic radiographs could be used easily to the confirmation of the Angle's clinical classification. The closed mouth panoramic radiography showed an advantage of maxillar and mandibular bilateral visualization, instead of the right and left sides overlapping as it occurs in the usually used cephalometric radiography. The closed mouth panoramic radiography showed an advantage of maxillar and mandibular bilateral visualization, instead of the right and left sides overlapping as it occurs in the usually used cephalometric radiography. The orofacial pain did not influence the upper airways

Comparative study of seasonal variability in peak expiratory flow rate amongst school children in rural and urban areas

Background: Peak Expiratory Flow (PEF) is a value test for lung function and can be conveniently measured by using relatively inexpensive and portable Peak Flow Meter, identifying and assessing the degree of airflow limitation of individuals. While PEFR is obviously related to factors like age, weight, height, race, gender, it may also be additionally affected by seasons and climate. The purpose of study being to observe seasonal variation in PEFR amongst school going children and to observe peak expiratory flow rate in school going children in urban and rural areas.Methods: This prospective and comparative study was carried out on total 600 children; with 300 each from rural and urban schools, of age group 10-14 years, both sexes. Peak expiratory flow meter was used for the measurements in the seasons of summer (April to June) and winter (December to February) of the year. The results thus obtained were compiled and analysed.Results: The mean PEFR value (Litres/min) during summers in the rural children was 243.50(S.D.=16.050) while during winters was 253.63(S.D.=16.934), highly significant (p<0.001); mean PEFR summers in the urban children was 241.50(S.D.=20.530)and during winters was 249.93(S.D.=21.685), again highly significant (p<0.001).In both rural and urban groups PEFR values increased with increase in height and weight of the children which was found to be highly significant (p<0.001). Girls representation proportion in rural vs urban schools being 49% vs 45%; whereas boys being 51% vs 55% respectively.Conclusions: Peak expiratory flow rate decreased during summer season of the year in both rural and urban school attending children. In both the groups PEFR values had a direct correlation with height and weight of the children. Rural schools showed more girl student representation than their urban counterparts indicating more awareness for girl child education amongst rural population.

Assessment of nasal airflow and pain, safety and cost of an improvised nasal airway (nasogastric) tube after endoscopic sinus surgery

@#Objective: To compare subjective nasal airflow and overall pain score (as well as safety and added cost of) using an improvised nasal airway tube (nasogastric tube) versus nasal packing after endoscopic sinus surgery (ESS) for chronic rhinosinusitis with nasal polyposis (CRSwNP). Methods: Design: Quasi - Experimental Prospective Cohort Study Setting: Tertiary Government Training Hospital Participants: Twenty-six (26) consecutive patients aged 18 to 77 years old diagnosed with CRSwNP who underwent ESS were alternately assigned to an experimental group (A) of 13, where an improvised nasal airway (nasogastric) tube was placed in addition to the nasal pack or a control group (B) of 13 with nasal packing alone. Results: There was a significant difference in subjective nasal airflow between experimental (A) and control (B) groups during the immediate postoperative period where the mean subjective airflow was 8.07 and 0.00 over 10.00, respectively. No significant difference was noted between the groups in terms of age, gender, severity of polyposis and overall pain score. No complications such as bleeding, Toxic Shock Syndrome, vestibular or alar injury and septal necrosis were noted immediately post-op and after one week follow-up in both groups. An approximate cost of PhP 25 was added to group A. Conclusion: An improvised nasal airway using a nasogastric tube provides adequate airflow without additional pain in the immediate postoperative period. It is safe to use and an affordable option for patients in need of nasal airway stents residing in areas where a preformed nasal packing with incorporated tube stent is not available.

Body mass index, obstruction of the airflow, dyspnea, and exercise capacity index as predictor of the severity of exacerbations and systemic involvement in patients with COPD

Background: Allocation of the limited resources to the needed patients and decision making regarding timely interventions demand development of a reliable, cost effective, simple assessment tool. Several studies propose body-mass index, airflow obstruction, dyspnea, and exercise (BODE) index for this purpose in patients with Chronic obstructive pulmonary disease (COPD). The objective of this study was to assess the utility of BODE index to predict the severity of exacerbations and systemic involvement in COPD.Methods: A Present hospital based cross sectional study was carried out among 100 COPD patients. BODE index was used to assess the patients and its association was studied with various variables. The data was analyzed using one-way analysis of variance (ANOVA) test.Results: As the body index class of severity increases, the number of hospitalizations required in the past also increases and this association is statistically significant. As the severity of the disease increased as indicated by the class the mean number of exacerbations in the past increased and this association was found out to be statistically significant. As the severity of the disease increased as indicated by the class level, the mean number of days of hospitalization increased. But this increase was of small difference and hence on one-way ANOVA test was not found out to be statistically significant. As the pack years increases, the BODE index increases significantly (p value <0.001). As the severity of the disease increased, the mean body mass index decreased. Haemoglobin level was found to decrease with increase in BODE index class of severity. This association was statistically significant.Conclusions: The BODE index has been found to be a very good tool to assess the prognosis of COPD as well as severity of acute exacerbations.

Characteristics of Airflow in Lower Respiratory Tract of ARDS Patients / 医用生物力学

Objective To study the airflow characteristics in lower respiratory tract of acute respiratory distress syndrome (ARDS) patients with different degrees of respiratory distress by using computational fluid dynamics (CFD) technology. Methods Three-dimensional model of lower respiratory tract from a healthy subject was established based on CT image data. Standard k-ε turbulence model was used to simulate the airflow in lower respiratory tract, and the distribution characteristics of air velocity, airflow rate, air pressure and wall shear stress (WSS) in lower respiratory tract were analyzed. Results The function relationship between the pressure drop of airflow in lower respiratory tract and the respiratory intensity was fitted. The distribution characteristics of air velocity, air pressure and WSS in lower respiratory tract were obtained, and the airflow distributions in the lungs and the bronchi of each lobe were also obtained. Conclusions More detailed data of lower respiratory airflow field can be obtained by CFD simulation analysis, which provides the theoretical basis for clinical treatment of ARDS patients.

What is the impact of positive airway pressure in nasal polyposis? An experimental study

Introduction: It has been hypothesized that increasing the interstitial hydrostatic pressure within the sinonasal mucosa of patients with nasal polyposis (NP) might decrease the size of nasal polyps. Objective: To evaluate the effects of positive airway pressure, delivered by a continuous positive airway pressure (CPAP) device, in patients with NP and in control subjects. Methods: Twelve patients with NP and 27 healthy subjects were exposed to CPAP (20 cm H2O) for 2 hours. Visual analog scale (VAS), Nasal Obstruction Symptom Evaluation (NOSE) scale, acoustic rhinometry (AR), peak nasal inspiratory flow (PNIF) and nasal endoscopy (NE-Meltzer polyp grading system) were performed before and after the intervention, for all patients. Results: The control group showed a significant worsening in nasal obstruction symptoms, as measured by VAS and NOSE (p < 0.01), and a significant decrease in nasal patency, as measured by the PNIF and AR (p < 0.01). For the NP group, VAS, NOSE, and AR did not differ significantly (p = 0.72, p = 0.73, and p = 0.17, respectively), but PNIF values worsened (p = 0.04) after exposure to CPAP. There was a statistically significant reduction in the nasal polyps' size (p = 0.04). Conclusions: Positive pressure worsened the nasal obstruction symptoms and decreased objective parameters of nasal patency in control subjects. In patients with NP, exposure to CPAP reduced the nasal polyps' size, and the nasal patency, asmeasured by PNIF. However, it had no significant effects in AR and in nasal obstruction symptoms (AU)

Assessing Airflow Limitation among Smokers in a Primary Care Setting

Background: Many smokers have undiagnosed chronic obstructive pulmonary disease(COPD), and yet screening for COPD is not recommended. Smokers who know that they haveairflow limitation are more likely to quit smoking. This study aims to identify the prevalence andpredictors of airflow limitation among smokers in primary care.Methods: Current smokers ≥ 40 years old who were asymptomatic clinic attendees in aprimary care setting were recruited consecutively for two months. We used a two-step strategy.Step 1: participants filled in a questionnaire. Step 2: Assessment of airflow limitation using apocket spirometer. Multiple logistic regression was utilised to determine the best risk predictorsfor airflow limitation.Results: Three hundred participants were recruited. Mean age was 58.35 (SD 10.30) yearsold and mean smoking history was 34.56 pack-years (SD 25.23). One in two smokers were found tohave airflow limitation; the predictors were Indian ethnicity, prolonged smoking pack-year historyand Lung Function Questionnaire score ≤ 18. Readiness to quit smoking and the awareness ofCOPD were low.Conclusions: The high prevalence of airflow limitation and low readiness to quit smokingimply urgency with helping smokers to quit smoking. Identifying airflow limitation as an additionalmotivator for smoking cessation intervention may be considered. A two-step case-finding methodis potentially feasible.

The impact of different doses of azithromycin maintenance treatment on expiratory flow limitation and quality of life among stable patients with non-cystic fibrosis bronchiectasis / 中国医师进修杂志

Objective To observe the benefits and safety of different maintenance doses of azithromycin for long-term treatment in adult patients with non-cystic fibrosis (CF) bronchiectasis. Methods One hundred and thirty-two indigenous outpatients (>18 years old) with stable non-CF bronchiectasis were enrolled. All patients were randomly assigned to a control group and two treatment groups. Patients in the azithromycin fixed-dose treatment group received oral azithromycin (250 mg daily) and ambroxol hydrochloride (30 mg, 3 times/d). Azithromycin progressively decreased dosage treatment group received oral azithromycin (250 mg daily for 8 weeks-250 mg 3 times/week for 8 weeks-250 mg 2 times/week for 10 weeks) and ambroxol hydrochloride (30 mg, 3 times/d). Subjects in control group only received ambroxol hydrochloride therapy. The course of treatment lasted for 26 weeks. Spirometry, exacerbations, sputum microbiology, quality of life, dyspnea scores and adverse effects were monitored after treatment for 26 weeks. Results One hundred and twenty-nine evaluable subjects completed the study. After treatment, the level of percentage of estimated value forced expiratory volume in 1 second (FEV1% Pred) in azithromycin fixed-dose treatment group and azithromycin progressively decreased dosage treatment group was significantly higher than that before treatment: (83.01 ± 5.79)% vs. (79.39 ± 3.53)%, (84.97 ± 5.10)% vs. (80.94 ± 3.46)%, P<0.05. Forced expiratory flow between 25% and 75% of vital capacity (FEF25%- 75%) was also increased in two groups: (54.87 ± 5.72) % vs. (51.86 ± 8.16)%, (55.65 ± 3.39)% vs. (53.46 ± 5.75)% , there was significant difference (P<0.05). But the levels of above parameters between two groups after treatment had no significant differences (P >0.05). The parameters of FEV1% Pred, forced expiratory volume in 1 second (FEV1)/forced ventilatory capacity (FVC) and FEF25%-75%were lower compared to those before treatment in the control group (P <0.05). However, the scores of LRTI-VAS and FACED in control group after treatment were decreased slightly: (20.55 ± 1.76) scores vs. (21.34 ± 1.86) scores, P<0.05; (4.16 ± 0.75) scores vs. (4.36 ± 0.72) scores, P > 0.05. Seven episodes of acute exacerbation was occured during 26 weeks, 2 cases exited. The others did not interrupt azithromycin treatment during acute exacerbation. Drug-related adverse reactions were mild. Conclusions For adult stable patients with non-CF bronchiectasis, the clinical symptoms and airflow limitation are improved after long-term treatment of low-dose azithromycin. Similar effects on FACED score and LRTI-VAS score are observed in patients with progressively decreased dosage of azithomycin.

Association of metabolic syndrome with the severity of airflow obstruction in patients with chronic obstructive pulmonary disease / Journal of the ASEAN Federation of Endocrine Societies

@#<p><strong>BACKGROUND.</strong> Metabolic Syndrome (MetS) is common in Chronic Obstructive Pulmonary Disease (COPD) patients but their association is still an unsettled issue. The aim of this study was to determine the association of MetS with the severity of airflow obstruction.</p><p><strong>METHODOLOGY.</strong> This was a cross-sectional analytic study of 157 patients with COPD. They were classified using the Global Initiative for Chronic Obstructive Lung Diseases (GOLD). MetS was assessed using two well-recognized criteria. Demographics, clinical data, lifestyle-related characteristics, fasting blood sugar (FBS) and lipid profile were obtained. Multiple logistic regression was used to determine the association of MetS with the severity of airflow obstruction.</p><p><strong>RESULTS.</strong> 40.13% and 17.20% of patients had MetS using the NCEP/ATP III-AHA/NHBLI and IDF criteria, respectively. MetS was not associated with severity of airflow obstruction. Of the MetS components, only elevated blood pressure (BP) was significantly associated with severity of airflow obstruction (GOLD II: OR=3.28, p<0.001; GOLD III: OR=4.04, p=0.2; GOLD IV: OR=6.21, p=0.04). Elevated FBS was also associated with GOLD IV (OR=16.09, p=0.02). Significant factors associated with MetS in COPD patients were body mass index, inhaled steroid, number of pack-years, and GOLD II.</p><p><strong>CONCLUSION.</strong> MetS is not associated with severity of airflow obstruction. Only certain components of MetS showed significant associations such as elevated BP with GOLD II-IV and elevated FBS with GOLD IV.</p>

The pathological changes of visceral pleura in patients with chronic obstructive pulmonary disease / 天津医药

Objective To observe the pathological change of visceral pleura in patients with chronic obstructive pulmonary disease (COPD), and to discuss the relationship between the changes and COPD airflow limitation. Methods A total of 70 patients received the pulmonary lobectomy or partial resection because of lung tumor in Tianjin Chest Hospital from May 2014 to August 2015 were selected in this study. According to the results of pulmonary function test, the patients were divided into COPD group [forced expiratory volume in one second (FEV1)/ forced vital capacity (FVC) 0.05). The visceral pleural thickness and the proportion of elastic fibers in visceral pleural were significantly thinner in COPD group than those of control group ( P0.05). Conclusion The thinner visceral pleural and the reduction of elastic fibers in visceral pleural are one of the causes of expiratory airflow limitation in COPD patients.

Associations between airflow obstruction and the risks of morbidity on major chronic diseases in Chinese adults: a prospective cohort study / 中华流行病学杂志

Objective To examine the prospective associations between airflow obstruction (AFO) and risks of major chronic diseases morbidity in Chinese adults.Methods Samples of this study were from the China Kadoorie Biobank.A total of 486 996 participants aged 30 to 79 years (mean 51.5 years) at the baseline study,were included after excluding those who self-reported of having heart disease,stroke and cancer at baseline.AFO was defined under the Global Initiative on Obstructive Lung Disease (GOLD) criteria and forced expiratory volume per one second in percentage of the expected one (FEV1％P).Cox regression models were used to investigate the associations of AFO with incidence rates of ischemic heart disease,cerebrovascular disease and lung cancer after adjusted for potential confounders.Results Over a period of 7 years through the follow-up program,the incident cases of ischemic heart disease,cerebrovascular disease and lung cancer appeared as 24 644,36 336 and 3 218,respectively.Compared with people without AFO,the HR (95％CI) of GOLD-1 to GOLD-4 were 0.89 (0.78-1.01),1.05 (0.98-1.12),1.29 (1.18-1.40) and 1.65 (1.42-1.91) respectively for ischemic heart disease.The HR (95％ CI) of GOLD-1 to GOLD-4 were 0.96 (0.70-1.26),1.12 (0.96-1.31),1.38 (1.14-1.65) and 1.48 (1.05-2.02) respectively for lung cancer.No statistically significant differences in the associations between GOLD level and cerebrovascular disease morbidity were found.However,each 10％ decrease in FEV1％P was associated with 7.2％ (95％CI:6.4％-8.0％),3.6％ (95％CI:3.0％-4.3％) and 10.5％ (95％CI:8.4％-12.6％) increased the risks of ischemic heart disease,cerebrovascular disease and lung cancer respectively.The results were persistant when stratified by smoking status.Conclusion Higher degree of AFO seemed to be associated with the risks of ischemic heart disease,cerebrovascular disease and lung cancer morbidity among the Chinese adults.

Associations between airflow obstruction and the risks of morbidity on major chronic diseases in Chinese adults: a prospective cohort study / 中华流行病学杂志

Objective To examine the prospective associations between airflow obstruction (AFO) and risks of major chronic diseases morbidity in Chinese adults.Methods Samples of this study were from the China Kadoorie Biobank.A total of 486 996 participants aged 30 to 79 years (mean 51.5 years) at the baseline study,were included after excluding those who self-reported of having heart disease,stroke and cancer at baseline.AFO was defined under the Global Initiative on Obstructive Lung Disease (GOLD) criteria and forced expiratory volume per one second in percentage of the expected one (FEV1％P).Cox regression models were used to investigate the associations of AFO with incidence rates of ischemic heart disease,cerebrovascular disease and lung cancer after adjusted for potential confounders.Results Over a period of 7 years through the follow-up program,the incident cases of ischemic heart disease,cerebrovascular disease and lung cancer appeared as 24 644,36 336 and 3 218,respectively.Compared with people without AFO,the HR (95％CI) of GOLD-1 to GOLD-4 were 0.89 (0.78-1.01),1.05 (0.98-1.12),1.29 (1.18-1.40) and 1.65 (1.42-1.91) respectively for ischemic heart disease.The HR (95％ CI) of GOLD-1 to GOLD-4 were 0.96 (0.70-1.26),1.12 (0.96-1.31),1.38 (1.14-1.65) and 1.48 (1.05-2.02) respectively for lung cancer.No statistically significant differences in the associations between GOLD level and cerebrovascular disease morbidity were found.However,each 10％ decrease in FEV1％P was associated with 7.2％ (95％CI:6.4％-8.0％),3.6％ (95％CI:3.0％-4.3％) and 10.5％ (95％CI:8.4％-12.6％) increased the risks of ischemic heart disease,cerebrovascular disease and lung cancer respectively.The results were persistant when stratified by smoking status.Conclusion Higher degree of AFO seemed to be associated with the risks of ischemic heart disease,cerebrovascular disease and lung cancer morbidity among the Chinese adults.

The Airflow Obstruction and Subjective Health Status Among Stable Chronic Obstructive Pulmonary Disease Patients Residing in the Community

PURPOSE: This study was undertaken to examine the relationship between airflow obstruction and subjective health status reported by stable patients with chronic obstructive pulmonary disease (COPD) residing in the community. METHODS: A cross-sectional descriptive study was conducted with 78 stable COPD patients aged 69.7 years old on average and selected by a convenient sampling from an outpatient department of pulmonology in tertiary hospitals. They completed a constructed questionnaire including general characteristics, smoking history, dyspnea by modified medical research council (mMRC) scale, and health status by COPD assessment test (CAT). Anthropometric measurements were performed for body mass index (BMI) and pulse oxymetry for O₂ saturation (Sat O₂). Medical records were reviewed to obtain disease-related characteristics including duration of the disease, cardiovascular comorbidity, and forced expiratory volume in 1 second (FEV₁). Data were analyzed using PASW statistics 20.0. RESULTS: Mean FEV₁% and CAT scores were 55.11% and 17.73, respectively. Those in the lower stage of mMRC showed significantly higher FEV1 and lower CAT. FEV1 and CAT showed significant negative correlations; age and BMI with FEV₁, and Sat O₂ with CAT. CONCLUSION: The findings suggest that the less airway obstruction was, the better health status was, and provide the support for using subjective measures in clinical practices for COPD patients.

Influential factors of airflow limitation in patients with chronic obstructive pulmonary disease:an analysis using quantitative CT / 实用放射学杂志

Objective To evaluate the correlations of emphysema and airway wall thickness to chronic obstructive pulmonary disease(COPD) of airflow limitation by quantitative CT.Methods 40 COPD patients and other 40 normal controls underwent pulmonary function tests and following MSCT exams with inspiration.The square root of wall area of an airway with an internal area of 8 mm2 (Ai8) and the percentage of low attenuation volume(LAV%) of the whole lung and each lobes at the threshold of-950 HU were measured by a software of Thoracic VCAR.The Ai8 between the observation group and the control one was compared using SPSS2.2.The contributions of LAV% and Ai8 to predictions of FEV1/FVC and FEV1% were also evaluated.Results There was a significantly statistical difference in the Ai8 between the observation group and the control one.There were correlations between airflow limitation markers and all of LAV% as well as Ai8 (P<0.05 for all standardized coefficients).Only the Ai8 of right inferior lobar made a significant contribution to airflow limitation in the whole lung bronchus, and the LAV% of each lobes made a stronger contribution to airflow limitation than the Ai8 of right inferior lobe.Conclusion There is a significantly statistical difference in the Ai8 between the observation group and the control one.The LAV% may make a greater contribution to airflow limitation than Ai8 in COPD group.The influential factors of airflow limitation in order were LAV%, Ai8 of right inferior lobe and Ai8 of the other lobes.

Pale nasal mucosa affects airflow limitations in upper and lower airways in asthmatic children

BACKGROUND: Severe asthmatics are thought to have severer rhinitis than mild asthmatics. A pale nasal mucosa is a typical clinical finding in subjects with severe allergic rhinitis. OBJECTIVE: The aim of this study was to investigate whether a pale nasal mucosa affects airflow limitations in the upper and lower airways in asthmatic children. METHODS: Rhinomanometry, nasal scraping, and spirometry were performed in 54 asthmatic children (median age, 10 years). The nasal mucosa was evaluated by an otolaryngologist. Thirty-seven patients were treated with inhaled corticosteroids, and 11 patients were treated with intranasal corticosteroids. RESULTS: Subjects with a pale nasal mucosa (n = 23) exhibited a lower nasal airflow (p < 0.05) and a larger number of nasal eosinophils (p < 0.05) in the upper airway as well as lower pulmonary functional parameters (p < 0.05 for all comparisons), i.e., the forced vital capacity (FVC), the forced expiratory volume in 1 second, and the peak expiratory flow, compared with the subjects who exhibited a normal or pinkish mucosa (n = 31). No significant difference in the forced expiratory flow between 25%–75% of the FVC, regarded as indicating the peripheral airway, was observed between the 2 groups. CONCLUSION: A pale nasal mucosa may be a predictor of eosinophil infiltration of the nasal mucosa and central airway limitations in asthmatic children. When allergists observe a pale nasal mucosa in asthmatic children, they should consider the possibility of airflow limitations in not only the upper airway, but also the lower airway.

Investigation on the nasal airflow characteristics of anterior nasal cavity stenosis

We used a computational fluid dynamics (CFD) model to study the inspiratory airflow profiles of patients with anterior nasal cavity stenosis who underwent curative surgery, by comparing pre- and postoperative airflow characteristics. Twenty patients with severe anterior nasal cavity stenosis, including one case of bilateral stenosis, underwent computed tomography (CT) scans for CFD modelling. The pre- and postoperative airflow characteristics of the nasal cavity were simulated and analyzed. The narrowest area of the nasal cavity in all 20 patients was located within the nasal valve area, and the mean cross-sectional area increased from 0.39 cm2 preoperative to 0.78 cm2 postoperative (P<0.01). Meanwhile, the mean airflow velocity in the nasal valve area decreased from 6.19 m/s to 2.88 m/s (P<0.01). Surgical restoration of the nasal symmetry in the bilateral nasal cavity reduced nasal resistance in the narrow sides from 0.24 Pa.s/mL to 0.11 Pa.s/mL (P<0.01). Numerical simulation of the nasal cavity in patients with anterior nasal cavity stenosis revealed structural changes and the resultant patterns of nasal airflow. Surgery achieved balanced bilateral nasal ventilation and decreased nasal resistance in the narrow region of the nasal cavity. The correction of nasal valve stenosis is not only indispensable for reducing nasal resistance, but also the key to obtain satisfactory curative effect.

Human microbiome studies in Korea

During the second half of the 2000s, the significant impact of human microbiome on human diseases and health conditions was found. Since the Human Microbiome Project, many microbiome studies have been reported in domestic and international references. Gastrointestinal tract microbiome has been most investigated so far, and the association with illness has been demonstrated in many diseases. Recently, the range of study was extended to multiple human organs, such as the respiratory tract, skin, and urogenital tract. Given the scale and speed of research and development in recent years, the role of microbiome in many diseases would be established before long. In this review, we aimed to summarize the current status of microbiome studies in Korea and foreign countries with an emphasis on respiratory tract microbiome. The main concept and analytical methods for microbiome research, associations of microbiome and diseases, and research projects on Korean microbiome are reviewed.